1. Technical Field
The present invention relates to a cartridge charged with fluid materials, such as adhesive and sealant, and a cartridge-loading device for mounting such cartridge to fluid dispensing apparatuses (for example, a dispensing gun) capable of dispensing the fluid materials.
2. Related Art
Cartridges charged with fluid materials, such as adhesive and sealant, have a variety of kinds of practical applications.
Usually, a cartridge is mounted to fluid dispensing apparatuses with the aid of a device to load the cartridge thereto. Such device is known as a “loading device.” This loading device, in general, is equipped with a cylindrical device body of which both end sides are opened to form individual openings, a piston, and a nozzle. The piston is located inside the device body so as to be slidable along a bore of the device body. The nozzle is detachably attached to one of the openings of the device body.
The cartridge is provided with a cylindrical cartridge body made of a membrane. The opening of each end of the cartridge body is sealed by binding its end portion with the use of, for example, a relatively thin wire composing sealing means. The cartridge body is charged with a desired fluid material before the completion of sealing both ends of the cartridge body.
For loading the cartridge to the loading device, the piston is first pushed back sufficiently toward one of both ends in order to accept the cartridge entirely into the device body. The device body is placed to stand, and the cartridge is inserted into the bore of the device body from its upper opening. After the insertion, the upper end of the cartridge, which is on opposite side to the piston, is cut out by for example scissors at an inner position than the sealing means to form an opening. The nozzle is then forcibly fit into the other end of the device body, before the loading device is loaded onto a fluid dispensing apparatus such as a dispensing gun.
A rod of the dispensing apparatus is operated to push the piston toward the nozzle, with the result that the cartridge begins to be squeezed in turn from the piston side thereof in an accordion-like form. This squeezing operation allows the fluid material contained in the cartridge to be pushed out through the opening thereof, resulting in that the material is dispensed out of the nozzle.
When the whole cartridge has been squeezed, that is, the cartridge has been used up, it is possible to exchange the cartridge for a new one by removing the squeezed cartridge from the device body. This removal is achieved by removing the nozzle from the cartridge body, in which the squeezed cartridge forcibly sticks to the nozzle. That is, the cartridge is automatically pulled out, together with pulling of the nozzle, from the device body.
After completing the removal of the squeezed cartridge from the device body, a new cartridge is loaded to the loading device so that the fluid material can be dispensed again.
It is usual, as above, that the removal of the nozzle causes the cartridge to be pulled out from the device body as well, because the cartridge is made to forcibly stick to the inside of the nozzle. However, such a case is not always true. Specifically, there are some occasions where the outer surface of the squeezed cartridge tightly comes in contact with the inner wall surface of the device body. Hence a space partitioned by both of the cartridge and the nozzle within the bore of the device body is shielded in an airtight manner. In such a situation, when pulling the cartridge from the device body together with the nozzle gives rise to a negative pressure in the space partitioned by both of the cartridge and the nozzle. This negative pressure operates to pull back the cartridge toward the piston, resulting in that the cartridge is often left alone in the device body, not pulled out together with the nozzle operated by hands.
If such an occasion occurs, the cartridge should be pulled out again after having pulled out the nozzle. Pulling the cartridge out forces an operator to grip the nozzle-side end of the cartridge with operator's fingers, although the nozzle-side end thereof has been dirty with the fluid material. Therefore, manually pulling the cartridge that remained within the device body will lead to a problem that operator's hands become dirty with the fluid material.
In addition, the foregoing conventional cartridge has a problem that the fluid material is easier to spill over during loading work of the cartridge to the loading device. Specifically, when it is requested for an operator that the upper end of the cartridge be cut out to form an opening, it is considerably difficult for the operator to realize the cutting work without a spill of the fluid material charged within the cartridge. When such a spill occurs, the device body or an operator's hand will get dirty with the spilled fluid material.